f =open("f.txt","w+",encoding='utf-8')
content = ("中国是最伟大的国家","\n""我爱广金")
f.writelines(content)
f.seek(0)
for line in f.readlines():
    print()
f.close()
f = open("f.txt","a+",encoding='utf-8')
n = ('\n'"喂喂喂，看得到吗")
f.writelines(n)
f.seek(0)
for line in f:
    print(line)
f.close()